With mutants, genetic mosaics and physiological techniques it is proposed to analyze specifically the control of aging, flight mechanisms and the neuromuscular control of leg movements in Drosophila. Hyperkinetic 1 and Shaker 5 are neurological mutants of Drosophila with reduced life span as compared to their wild-type background stock. The reduction in longevity has been shown to be correlated with an increased activity level and rate of oxygen consumption. The longevity of gynandromorphs, mosaic for mutant tissues will be measured in order to determine whether an aging center can be uncovered. Flight mutants exist for which it is proposed to study physiologically mosaic individuals in order to find that part of the animal which is relevant to the abnormal behavior. The mutant focus can then be made available for histological, electrophysiological and ultimately, biochemical analysis. A new method for screening for autosomal mutants will be used to produce second-site mutants capable of modifying the phenotype of Hyperkinetic 1.